ABSTRACT This definition may not be instantiated
126.96.36.199.1 Semantic definition
IfcMaterialDefinition is a general supertype for all material related information items in IFC that have common material related properties that may include association of material with some shape parameters or assignments to identified parts of a component.
There are three ways of assigning materials to a single component or multiple components; they are characterized as:
- by layer - assigning a material to a layer with constant thickness
- by profile - assigning a material to a profile with a constant of varying shape along an extrusion
- by constituents - assigning a material to an identified part of a component shape; the identification is by a keyword rather than by a shape parameter
Each instantiable subtype of IfcMaterialDefinition may have material properties assigned, or have an external classification of its definition. It can be assigned to either a subtype of IfcElement, or a subtype of IfcElementType by using the objectified relationship IfcRelAssociatesMaterial.
188.8.131.52.2 Entity inheritance
|AssociatedTo||SET [0:?] OF IfcRelAssociatesMaterial FOR RelatingMaterial||
Use of the IfcMaterialDefinition subtypes within the material association of an element occurrence or element type. The association is established by the IfcRelAssociatesMaterial relationship.
|HasExternalReferences||SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects||
Reference to external references, e.g. library, classification, or document information, that are associated to the material.
|HasProperties||SET [0:?] OF IfcMaterialProperties FOR Material||
Material properties assigned to instances of subtypes of IfcMaterialDefinition.
184.108.40.206.4 Formal representation
ENTITY IfcMaterialDefinition ABSTRACT SUPERTYPE OF (ONEOF (IfcMaterial ,IfcMaterialConstituent ,IfcMaterialConstituentSet ,IfcMaterialLayer ,IfcMaterialLayerSet ,IfcMaterialProfile ,IfcMaterialProfileSet)); INVERSE AssociatedTo : SET [0:?] OF IfcRelAssociatesMaterial FOR RelatingMaterial; HasExternalReferences : SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects; HasProperties : SET [0:?] OF IfcMaterialProperties FOR Material; END_ENTITY;